Linear bearings or liners have been used to provide a flat guiding module or plate-type bearing elements for rolling stand frames. These bearings typically have at least one slide-bearing surface in contact with another bearing surface and are particularly prone to wear and tear within the hostile rolling environment. Versions of linear bearings are disclosed in PCT applications, PCT/EP02/03010 and PCT/EP03/014573, each document being incorporated by reference herein.
To obtain precisely rolled products, all clearances throughout the rolling system must be evaluated and held to tightest possible tolerances. Failure to maintain bearing clearances results in a substantial economic reduction of the product, increased maintenance costs, excessive component wear, and other dangerous conditions.
It has been recognized that bearing wear is often determined by outside influences and mechanical effects such as abrasion, chamfer wear and wear of mounting surfaces. Abrasion may result from scale and abrasive particles, severely worn bearing surfaces from any relative movement between chock and housing, corrosion and localized overloads. Chamfer wear may result in damaged chamfers, reduced bearing surface area, imprecise guidance during chock loading, and open passages for water and abrasive particles. Corrosion (or erosion) may be caused by cooling water chemicals, high pressure descaling water and shimming. Corrosion may result in washed out lubrication, increased humidity, fretting defects and pop-outs of liner material. Wear of liners may result from heavy impact loads, such as hammering, localized overloads and corrosion/erosion.